If animals can only see black and white, why are poisonous critters brightly colored?

Answer 1

Many animals can see color. Cones allow color vision, rods enable night vision.
Humans have three types of cones. Dogs and horses for example, only have two. This is why dogs see the color blue best (they don't see red and green) and horses can see the color green best.
Most animals probably don't see the full spectrum of color that us humans do, but that does not mean they are colorblind.

Answer 2

As was stated many animals do see colors but even the ones that don't must see a very unusual shade of gray. Like on the older black and white television sets when something was bright red you could just tell it was by the strange shade of gray. I had a quote here from this website.

According to Doug (who the heck is Doug?):

"The story behind aposematic coloration (the scientific term for "warning colors") is pretty simple. They are always bright, highly-contrasting patterns. Black and yellow is the most common, but black and orange, black and red, and black and white are also encountered. There are also a smattering of color combinations in very specific small groups of butterfly and moth species that involve other colors (like green and orange, blue and red, black and green), but always the rule of high contrast applies.

"These are organisms that want to be seen. It's to the advantage of a species if predators only have to eat (or attempt to eat) a small number (ideally only ONE) of individuals before they learn not to try it again. The more unique and memorable the appearance of something, the easier it is to learn not to mess with it. The result is that if you have a species which is losing, say, 5 out of every 10 individuals each generation to predators, and a brightly-colored mutant arises which loses only 1 out of every 100, the mutant will have a 50-fold advantage, and that mutant coloration gene will quickly replace the original version by natural selection.

"Naturally, in order for this to work properly, the critter(s) in question has to be poisonous or foul-tasting. If there are multiple species that all taste bad, they often will converge on the same color pattern so the predators learn even faster (called Mullerian mimicry). Once a system like this evolves, however, then other, non-toxic species will evolve to exploit it, which is called Batesian mimicry. If a mutant arises, say, in an edible butterfly species and it thereby happens to resemble an inedible one, then that mutant will spread because predators will avoid it, giving it a survival advantage. But it can only spread so long as the inedible originals greatly outnumber the edible mimics. If the mimics become too common, the predators will learn that the color pattern now signifies edibility, and the system will collapse."

Whomever Doug is I tend to believe him!!

Edit: Okay since those brightly colored snakes for example are eating small mammals a warning makes no sense to them, the prey, but the birds are going to eat the venomous snake so, at least now they know to be a bit more careful when they swoop out of the sky, interesting, on the box below...

Answer 3

First, your assumption that animals see in black and white is incorrect. Many animals do indeed see in color and those animals that have non-color vision, actually see all the 256 shades from white to black.

Critters that are brightly colored and have some form of toxicity have evolved that way as a mechanism for self protection. If the predators or potential predators could not see colors, then there would be no need for the colors of the toxic critters. See the logic? Evolution does not just do things independently, there has to be a sort of cause and effect, form and function.

If we extended your logic, then there would be no need for brightly colored male birds. OK? See what I am getting at?

Answer 4

I don't know where you get the idea that all animals only see in black and white, as it is incorrect. Quite a few animals have vision far superior to our own in some area, for instance eagles have extremely good panoramic vision. Big cats have night vision and so on. And a few are indeed color blind, but I believe that usually does not matter as the reason the animal evolved color blind is that they had no need for colored vision

Answer 5

Alot of animals can see in the colour spectrum different to humans, to them animals look alot different, and different colours give different shades of black and white, not all poisonous animals are brightly coloured i.e the black snake and some spiders are brown and black.

Answer 6

Very few animals see in black & white. Some have vision that can see colors better than we can, while others can see light frequencies that we cannot (infrared, ultraviolet, etc...)
Mostly animals that are primarily night hunters or otherwise nocturnal tend to have vision that is more black & white. Thats because you can see in black & white at much lower light levels than are needed for seeing in color.
Even we see in black & white only in very low light levels (you should try it!!), then when there is enough light, we start to see colors.

Answer 7

Not all animals only see in Black and white.

Answer 8

Birds have excellent color vision, so bright colors serve as a warning to them. Reptiles also have color vision. It is mammals that have little or no color vision, most of them anyway.
And it is birds and reptiles that eat most of the bugs.